Blender 2.8 sometimes freezes with imported file
I've just noticed that 3DS Max has an option to export OBJ file optimized for Blender.
That seems to be the solution apart from lowering the polycount on import from IGS file.

EDIT
After some tests i’ve got the following results:
Default import option: 15.858.388 triangles
Optimized import option: 557.088 triangles

Export to OBJ for Blender:
Default import + default export: 1.53Gb file (that’s a killer for Blender)
Optimized import + optimized export: 58.9 Mb